False Memory: What It Is, How It Forms and the Key Experiments

False memory at a glance

• What it is: a confident memory of an event or detail that is wrong in whole or in part.
• Main routes: misleading information after the event, associations between related ideas, imagination and suggestion, and confusion about where a memory came from.
• How common: everyday distortions are normal; in implantation studies about 30% of people form a false memory of a whole event.
• The hard part: false memories can be as vivid and as confidently held as true ones.
• Where it matters: eyewitness testimony, police and therapy interviews, family disputes and shared online myths such as the Mandela effect.

Why memory can be wrong

Psychologists describe remembering as reconstructive. When you recall an event, you do not retrieve a stored film; you put the event back together from pieces held in long-term memory, filling gaps with what usually happens and with what you have learned since. Personal events belong to episodic memory, and general knowledge can leak into them. Most of the time the result is good enough. False memories are the cases where the filling in becomes the memory.

Elizabeth Loftus, who has studied the subject for more than three decades, calls one central route the misinformation effect: memory for an event becomes impaired after exposure to misleading information about it. Her 2005 review notes that the effect has been observed in a variety of human and non-human species, that some groups of people are more susceptible than others, and that warnings about misinformation help only under limited circumstances.

The word-list illusion

The simplest way to create a false memory needs only a list of words. In 1995 Henry Roediger and Kathleen McDermott, building on a 1959 study by James Deese, read people lists of 12 words such as bed, rest, awake, tired. Every word was associated with one word that was never read out: sleep. On an immediate free-recall test, participants recalled the missing word 40% of the time, and later recognised it with high confidence. With a larger set of lists, false recall reached 55%, and on a recognition test the never-presented words were accepted about as often as words that had really been on the list.

The method, now called the DRM paradigm after Deese, Roediger and McDermott, has been used around the world. It shows that a false memory needs no deception at all: a strong enough association is enough.

Planting whole events

Could people be led to remember an entire childhood event that never happened? Since the 1990s researchers have tested this with what is known as the “lost in the mall” method: they suggest a childhood event that never happened, often alongside real ones, and interview participants about it several times.

• A doctored photograph. In 2002 Kimberley Wade and colleagues showed 20 adults a faked photograph of themselves as children on a hot-air balloon ride. Over three interviews with guided imagery, 50% created complete or partial false memories of the ride.
• The pooled estimate. A 2017 mega-analysis recoded the reports of 423 participants from eight published implantation studies with one consistent set of criteria. 30.4% were classified as false memories and another 23% accepted the event to some degree. When the suggestion contained self-relevant details and an imagination exercise, and came without a photograph, the rate rose to 46.1%.

False memories of committing a crime

In 2015 Julia Shaw and Stephen Porter reported that after three highly suggestive interviews, 70% of participants were classified as having false memories of committing a crime in adolescence that led to contact with the police, and gave detailed accounts of it. The false accounts had the same kinds of complex descriptive and multisensory detail as true memories.

The figure was soon challenged. In 2018 Kimberley Wade, Maryanne Garry and Kathy Pezdek recoded the same data. Using the original coding they reproduced the 70%, but when they separated people who seemed to remember the crime from those who merely came to believe it, 26–30% met the criteria for a false memory, in line with earlier studies. Both readings support the core finding: a suggestive interview can make people remember things they never did.

Can a false memory be undone?

Largely, yes. In 2021 Aileen Oeberst and colleagues at the University of Hagen in Germany, with researchers in Mainz and Portsmouth, first implanted false memories of two plausible childhood events suggested by the students’ parents, alongside two true events. After three interviews, 27% had developed false memories under minimally suggestive conditions and 56% under massive suggestion. A new interviewer then pointed out other possible sources of the memories, such as family stories, and explained that memory interviews can create false memories by accident. False-memory rates fell back to the level of the first interview, about 15% and 25%, while memories of the true events were barely affected. A year later the rate was 5%.

Does a high IQ or a great memory protect you?

Only partly. In a 2010 study of 436 college students in China, Bi Zhu, Elizabeth Loftus and colleagues found that false memories from misleading information were negatively correlated with intelligence, measured with Raven’s Advanced Progressive Matrices and the Wechsler Adult Intelligence Scale, as well as with perception and memory scores. People with higher scores were, on average, harder to mislead.

An exceptional memory is no shield, though. In 2013 Lawrence Patihis and colleagues tested people with highly superior autobiographical memory, the rare ability to recall almost every day of one’s life. They were just as prone as matched controls to falsely recognise the missing word in word lists and to report having seen non-existent footage of a plane crash, and in a misinformation task they showed more false memories than controls. Remembering more, it seems, still means reconstructing. For the related myth of perfect recall, see our page on photographic memory.

The Mandela effect

The Mandela effect is the internet name for false memories that many people share: that the Monopoly man wears a monocle, for example. In 2022 Deepasri Prasad and Wilma Bainbridge at the University of Chicago tested it. In a study of 100 adults, certain images of popular icons produced the same specific false memory across people. Eye-tracking-like methods found no difference in how those images are looked at, there was no clear difference in people’s everyday visual experience of them, and the same errors appeared when people recalled the icons freely. Why some images trigger shared errors remains open; the study shows only that the effect is real and specific.

Recovered memories and the “memory wars”

The most serious debate about false memory concerns memories of abuse said to have been forgotten for years and then recovered, often in therapy. The dispute of the 1990s, sometimes called the memory wars, is also where the phrase “false memory syndrome” comes from. Real abuse happens and is often remembered; the scientific question is narrower: whether purely psychological trauma can block a memory completely, and whether suggestive techniques can create memories of events that did not occur.

In 2019 Henry Otgaar and colleagues at Maastricht University, with researchers in the United States, argued that the debate is not over. They put belief in repressed memories at 58%, reported that it appears to have increased among clinical psychologists since the 1990s, and reviewed adverse side effects of some psychotherapeutic techniques. The paper is itself part of a continuing argument; the experimental evidence that suggestion can create detailed memories is the part that is well established.

False memory versus real memory

There is no reliable inner sign. Confidence, vividness, emotion and detail all appear in false memories too. A few practical points follow from the research:

• Look for independent evidence. Diaries, messages, photographs taken at the time and other witnesses are better tests than how certain a memory feels.
• Ask where a detail came from. Did you see it, or hear about it later, or see it in a photo or film? Mixing up the source is one way later information enters a memory.
• Be wary of repeated imagining. Imagination exercises raised false-memory rates in the implantation studies.
• Keep questions open. In interviews, “what happened?” adds nothing; a question that already contains an answer is one way misinformation gets in.
• Write it down early. A note made soon after an event is less exposed to later information than a story retold many times.

Memory errors interact with the way we weigh evidence. Our pages on confirmation bias and the availability heuristic explain how the memories that come to mind first shape judgement. If doubts about your own memories are causing you distress, a doctor or psychologist is the right person to talk to; this page cannot assess them.

Trust and scope notes

This page summarises published research for general information, with figures taken from the studies listed below. It is not medical or legal advice and does not diagnose any condition. The IQ Revealed test is an online reasoning test of 40 original items for adults aged 18 and over; it does not measure memory accuracy or susceptibility to false memories. Our guide to how IQ tests work explains what an online test can and cannot tell you.

IQ Revealed is not affiliated with, endorsed by or connected to the researchers, universities, journals or publishers named on this page, or with the owners of Raven’s Progressive Matrices, the Wechsler scales or the Monopoly brand. Names are used only to identify the research being described.